In the past, a method was known whereby in an solid oxide fuel cell system (SOFC), upon startup fuel gas discharged from multiple fuel cells was combusted, and as the reformer was heated using that combustion heat, a sequence was executed in accordance with each of the stages of startup including a partial oxidation reforming reaction (POX) of fuel gas, an auto-thermal reforming reaction (ATR), and an steam reforming reaction (SR), thereby raising the temperature of the reformer etc.
In fuel cells of this type, gas discharged from the fuel cell is ignited by ignition devices such as ignition heaters, igniters, and the like to start combustion.
However, it is not realistic from a cost standpoint to provide ignition devices for all of multiple fuel cells. Therefore ignition by an ignition device is performed only for fuel gas discharged from a portion of fuel cells, following which all fuel cells are ultimately ignited by causing flame to move to adjacent cells (see, for example, JP2008-135268A).